A morally, historically, socially, and politically childish amalgam of Pocahontas and Ferngully: The Last Rainforest, Avatar finds James Cameron--still the Cameron of Titanic (or the uncomfortably simpering T2, if we're honest with ourselves) rather than the Cameron of Aliens and The Terminator--trying his hand at being Kevin Costner: powerful, dim, and only relevant for a tiny window of time he doesn't realize has already closed. The more simple-minded liberal proselytizing he perpetrates like Avatar, the farther away he gets from the B-movie muscularity that indicated his early career. It's a bad thing, believe me, that the first set of movies...